Tool for grinding valve seats



June 26, 1934. L Q BEARD 1,964,240

TOOL FOR GRINDING VALVE SEATS Filed Jan. 22, 1934 Lawrence O Beard Patented June 26, 1934 TOOL FOR GRINDING VALVE SEATS Lawrence 0. Beard, Lancaster, Pa.

Application January 22 9 Claims.

My invention relates to a tool for grinding valve seatsand more particularly the conical seats formed in the motor blocks of internal combustion engines.

The principal object of the invention is to provide a tool having .a flexible paper or cloth abrasive element, mounted for ready removal upon a relatively stiff metal backing member, whereby the originalgcontour of the removable 3 abrasive element will be permanently maintained during successive use of the tool on valves of different diameters, while permitting ready renewal of the abrasive element when the latter becomes worn. 1

Another object of the-invention is to provide a tool adaptable for use with any standard make of pilot.

These and otherobjects will be apparent from the following description inwhich the same numerals designate similar parts in the several views.

In the drawing:

Figure 1 is a side elevation of the assembled tool in operative position;

Figure 2 is an exploded view of the several parts of the improved tool partly in section;

Figure 3 is a side elevation of the tapered shank and pilot stem;

Figure 4 is a plan view of the backing member or shell;

Figure 5 is a plan view of the grinding head;

Figure 6 is a plan view of the abrasive disk before being folded to conform to the shapeof the backing shell; and

Figure 7. is a plan'view of the clamping member for securing the abrasive member to the backing member or shell.

Referring more specifically to the drawing, the numeral 1 designates the tool generally comprising a downwardly tapered shank 2, of standard size having its lower end reduced in diameter to form the customary pilot stem 3, and 4 is a conically shaped grinding head having a cylindrical bore 5, adapted to loosely receive the shank 2, when the parts are assembled in a manner hereinafter described. The grinding head has a flat top surface 6 and a conical working surface 7 of suitable pitch or slope substantially merging at its lower end with the wall of bore 5. Relatively' deep square out grooves 8, preferably three in number, are cut radially into the grinding head 4 at a slightly decreased pitch from that of the cone working surface 7, the grooves extending from the top surface 6 to the bore 5. A bushing 9 having external screw threads 10 at its upper end and a flange 11 at its-lower end, is formed with a bore 12 tapered in a reverse direction to the taper of shank 2. When this bushing is inserted in the lower end of bore 5 of the grinding head, and a clamp nut 13 is screwed home on the threads 10 of the bushing,

, 1934, Serial No. 707,772

the grinding head. will be clamped tightly in place between the nut 13 and flange 11.

A removable supporting member 14 comprising a thin, flexible, non-resilient, conically shaped, open-ended metal shell 15, preferably of tin or like material, adapted to snugly fit the working face of grinding head 4, is formed with indented folds 16 which are tapered in depth from the top edge or rim 17 of the shell toward the bottom edge 17' thereof. These folds 16 are positioned to interfit with grooves 8 of thegrinding head. A thin circular disk of emery cloth or paper 18, or other suitable flexible abrasive material, having an aperture 19 constitutes the abrasivcelement for grinding a valve seat, not shown. The element or member 18 is sleeved over the conical face of the supporting shell 15, and caused to conform closely to the contour of the latter by means of a clamping member or spider 20,of the same thin, flexible but nonstretchable, non-resilient metal as the shell. Clamping member 20 comprises a narrow annulus or ring like portion 21, the inner diameter of which is just sufficient to permit of the clamping member being sleeved over the bushing or adapter 9 and in abutting relation with annular flange 11. Projecting upwardly and outwardly from the annulus 21 of clamping member 20, are a plurality of arms 22, one for each indented fold 16, in which folds these arms are adapted.

to snugly fit when the latter together with adjacent portions of the abrasive disk 18 are pressed thereinto. The length of arms 22 is such that their upper free ends 23 can be conveniently bent over the upper peripheral edge of shell 15 at the indented folds 16 and thence downwardly and rearwardly against the inner face of the shell, thus clamping the abrasive disk tightly but removably to the shell. When nut 13 is screwed on the upper end of bushing 9, the annulus 21, shell 15 and interposed abrasive disk 18 will be clamped against the annular flange 11 of bushing 9. Those portions of the disk 18 which are pressed by arms 22, into the folds 17, have their outer peripheral edges slightly out out as at 24 so that the margin of the disk within the fold will not extend over the margin of the fold and thus become frayed by the arms when the latter are folded over the disk. This also insures a closer fit between the parts.

It will be understood from the foregoing that the flange 11 of the bushing engages the annulus of the clamping member 20 and'the clamp nut 13 threadedly engages threads 10 and tightly clamps the grinding head and abrasive element 18 together. It will also be apparent that in forcing the grinding head down upon the valve seat by rotating the shank 2 that the tapered bore 12 of the bushing will tightly engage the shank and prevent the bushing andhead from relative rotation. A tight fit between the abrasive element 18 and the head 4 is assured by the interlocking engagement of the indented folds of the shell with the grooves 8 of the head, and it is thus impossible for them to become disengaged. The end of the shank 2 is squared as at 26, so that a wrench may be employed to grind the valve seat, or a rod may be inserted in circular hole 25 located below the squared end by means of. which the tool may be rotated.

To assemble my device I slip the clamp nut 13, grinding head 4 with the abrasive element 18 fitted thereon onto the stem 2, and slide the bushing 9 through the head and tightly thread the clamp nut 13 on the threaded portion 10 of the bushing, thus tightly clamping the abrasive element and the grinding head together. After inserting the head into the valve seat, the tool is rotated by means of either a wrench or rod, not shown.

What I claim is:

1. A tool for grinding valve seats comprising a shank having a conical grinding head mounted thereon, adapted to engage the valve seat, said head having recesses formed therein, a supporting member having indentations formed therein for interfitting with grooves in said head, an abrasive member removably associated with said supporting member, and clamping means for holding said abrasive member against said supporting member.

2. A tool for grinding valve seats comprising a shank having a conical grinding head mounted thereon adapted to engage the valve seat, said head having radial recesses formed therein, a thin flexible supporting member adapted to be placed over the said head, said supporting member having indented folds therein for interfitting with grooves in said head, an abrasive member superposed on said supporting member and a flexible clamping element for clamping the abrasive member against the supporting member.

3. A tool for grinding valve seats, comprising a shank having a pilot stem, a conical grinding head mounted on said shank and adapted to engage the valve seat, square cut radial recesses formed in said head, a metal shell adapted to be sleeved over the conical portion of said head, said shell having indented folds therein for interfitting with the grooves in the said head,' a disk of abrasive material carried by said shell, and a flexible metal clamping element for removably retaining the abrasive material against said shell, and means mounted on said shank for holding said shell and abrasive material in position against said grinding head.

4. A tool for grinding valve seats comprising a shank having a conical grinding head mounted thereon, adapted to engage the valve seat, relatively deep, square cut, radial recesses formed in said head, a thin metal shell adapted to be placed over and cover the conical portion of the said head, said shell having indented folds therein, one for each groove in the head, for interfitting with the said grooves, a disk of abrasive material substantially covering said shell, and a thin flexible, metal clamping element for clamping said disk against said shell, and means-inserted in said head and on said shank for holding said abrading material in position against said grind- 11 8 h ad- 5. A tool for grinding valve seats comprising a shank having a pilot stem thereon, a conical shaped grinding head mounted on said shank adapted to engage the valve seat, said head having a relatively deep, square ut, tapered, radial grooves formed at intervals therein, a conical shell formed v! a thin sheet of metal adapted to be placed over and cover the conical portion of the head, said shell having radial tapered grooves therein corresponding and interfitting with the grooves in said head, an integral disk of abrasive material adapted to fit snugly over said shell, a thin flexible metal clamping member having arms adapted to fit in the grooves formed in the shell for holding the abrasive disk against said shell, a bushing having a tapered bore adapted to fit between the bore of the head and the shank and a clamp nut engaging the end of said bushing for retaining the grinding head and abrading element in position against the stem.

6. A tool for grinding valve seats comprising a shank, a conical grinding head mounted on said shank adapted to engage the valve seat, said grinding head having grooves formed therein, a metal backing member adapted to be placed over said head and having indented folds therein for fitting in said grooves, a fiexible'abrasive member removably associated with said backing member, a flexible metal clamping member having arms adapted to clamp said member against said backing member and angularly disposed portions on said arms for retaining the abrasive member in position against the backing member.

'7. A tool for grinding valve seats comprising a shank, a conical grinding head mounted thereon adapted to engage the valve seat, grooves formed in said head, a metal backing member adapted to be placed over said head and having indented folds therein interfitting with said grooves, an abrasive member removably associated with said backing member, a thin flexible clamping member having arms of greater length than the depth of the backing membenfitting in said folds, a portion of said arms being bent over and clamped to the upper margin of said backing member to retain the abrasive disk in fixed position.

8. A tool for grinding valve seats comprising a shank, a conical grinding head fixedly mounted on said shank, a fiexible metal backing member removably associated with said head, and means on said grinding head and said backing member for holding them together against relative movement, an abrasive member mounted on said backing member, and a clamping member having arms thereon, and means'on said arms for clamping said abrasive disk against said backing member.

9. A tool for grinding valve seats comprising a shank having a conical grinding head mounted thereon, a flexible metal backing member removably associated with said head, and means on said grinding head and said backing member for holding them together against relative movement, an abrasive member mounted on said backing member, and a flexible metal clamping member having arms'of greater length than the backing member, the free ends of said arms being bent over the upper margin of said backing member and thence downwardly and inwardly against said backing member for holding said abrasive member removably to said backing member.

LAWRENCE O. BEARD. 

